$(function(){
  let $btn = $('input'),
      delay = 6,
      timer = null;

  $btn.val('同意('+delay+'s)');
  $btn.attr('disabled','disabled');

  timer = setInterval(()=>{
    $btn.val('同意('+ --delay +'s)');
    if (delay===0){
      clearInterval(timer);
      $btn.val('同意');
      $btn.removeAttr('disabled');
    }
  },1000);


  $btn.click(()=>{
    alert('butten clicked!');
  });
});
